The Democratic Congressional Campaign Committee is weighing into the special election in New York’s 20th district with a television ad buy. According to knowledgeable sources, the buy is scheduled to start on Friday and continue through March 31, the date of the special election. Specific details about the size of the DCCC’s buy are not yet known. The committee previously was on the air with a radio ad. On Thursday, the National Republican Congressional Committee went on the air with about 1,200 gross ratings points of television ads on broadcast and cable in the Albany media market, which covers the majority of the district. State Assembly Minority Leader Jim Tedisco (R) and venture capitalist Scott Murphy (D) are squaring off in the race to replace appointed Sen. Kristen Gillibrand (D).